The company's chief operating officer Paul Sams told Digital Spy that adapting Hearthstone for smaller-screen devices was a challenge for the development team.

"It's not excruciatingly difficult to build a tablet game when you know how to code for PC. That's been really positive and has not been a huge learning curve for us," he explained.

"What is more difficult is to be able to bring Hearthstone to a smaller screen like an iPhone or an Android device, because we've got to mess with the UI a bit to make sure it's a great experience on a small screen."